From: Karsten Graul kgraul@linux.ibm.com
[ Upstream commit 587acad41f1bc48e16f42bb2aca63bf323380be8 ]
Coverity reports a possible NULL dereferencing problem:
in smc_vlan_by_tcpsk(): 6. returned_null: netdev_lower_get_next returns NULL (checked 29 out of 30 times). 7. var_assigned: Assigning: ndev = NULL return value from netdev_lower_get_next. 1623 ndev = (struct net_device *)netdev_lower_get_next(ndev, &lower); CID 1468509 (#1 of 1): Dereference null return value (NULL_RETURNS) 8. dereference: Dereferencing a pointer that might be NULL ndev when calling is_vlan_dev. 1624 if (is_vlan_dev(ndev)) {
Remove the manual implementation and use netdev_walk_all_lower_dev() to iterate over the lower devices. While on it remove an obsolete function parameter comment.
Fixes: cb9d43f67754 ("net/smc: determine vlan_id of stacked net_device") Suggested-by: Julian Wiedmann jwi@linux.ibm.com Signed-off-by: Karsten Graul kgraul@linux.ibm.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/smc/smc_core.c | 35 ++++++++++++++++++----------------- 1 file changed, 18 insertions(+), 17 deletions(-)
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index d672c0f0e247f..508a14fc4f587 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -1596,14 +1596,26 @@ static void smc_link_down_work(struct work_struct *work) mutex_unlock(&lgr->llc_conf_mutex); }
-/* Determine vlan of internal TCP socket. - * @vlan_id: address to store the determined vlan id into - */ +static int smc_vlan_by_tcpsk_walk(struct net_device *lower_dev, + struct netdev_nested_priv *priv) +{ + unsigned short *vlan_id = (unsigned short *)priv->data; + + if (is_vlan_dev(lower_dev)) { + *vlan_id = vlan_dev_vlan_id(lower_dev); + return 1; + } + + return 0; +} + +/* Determine vlan of internal TCP socket. */ int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini) { struct dst_entry *dst = sk_dst_get(clcsock->sk); + struct netdev_nested_priv priv; struct net_device *ndev; - int i, nest_lvl, rc = 0; + int rc = 0;
ini->vlan_id = 0; if (!dst) { @@ -1621,20 +1633,9 @@ int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini) goto out_rel; }
+ priv.data = (void *)&ini->vlan_id; rtnl_lock(); - nest_lvl = ndev->lower_level; - for (i = 0; i < nest_lvl; i++) { - struct list_head *lower = &ndev->adj_list.lower; - - if (list_empty(lower)) - break; - lower = lower->next; - ndev = (struct net_device *)netdev_lower_get_next(ndev, &lower); - if (is_vlan_dev(ndev)) { - ini->vlan_id = vlan_dev_vlan_id(ndev); - break; - } - } + netdev_walk_all_lower_dev(ndev, smc_vlan_by_tcpsk_walk, &priv); rtnl_unlock();
out_rel: